Southern California Endodontics

Antibiotics and MTA

Antibiotic Use and Misuse

There are some endodontic situations where it is appropriate to prescribe antibiotics:

• Non-vital pulp with good drainage upon opening the tooth.
• Non-vital pulp with fluctuant swelling where an incision and drainage is performed.
• Retreatment of a failing original root canal.
• Premedication situations, e.g. cardiac prophylaxis.
• Non-vital pulp in a medically comprimised patient.
• Non-vital pulp with an indurate, non-fluxuating swelling.
• Post-treatment swelling.

In these situations there is often a fever present of greater than 100 degrees.

MTA (Mineral Trioxide Aggregate)

Mineral trioxide Aggragate (MTA) is a 'wonder drug' in endodontics. It has shown significant improvement over other materials in promoting the pulp and periradicular tissues. Some of these applications will be discussed below.

MTA has been developed by researchers at the Department of Endodontics at Loma Linda University. Over the last five years, it has undergone extensive scientific testing and numerous articles documenting this research have been published in the Journal of Endodontics and in other periodicals. Long term clinical studies are planned.

Pulp capping has traditionally been performed with Calcium Hydroxide. MTA has now been shown to be more effective. It prevents bacterial leakage, is biocompatible and is effective in a moist environment. When placed over vital uninflamed tissue, it actually stimulates the formation of dentin.

The ideal situation is capping a young tooth with an incompletely formed root and an apical diameter of 1mm or more. It is essential that teeth be free of irreversible inflammation. Endodontic therapy is indicated in the presence of the large carious exposures or with teeth exhibiting spntaneous pain or lingering pain to thermal testing.

Another application of MTA is for root-end filling. It is technique sensitive and can be washed out easily with a saline rinse. perforation repair is becoming somewhat more predictable with MTA than with other materials such as Ketac Silver, amalgam, IRM and Gerestore. The key is to repair these defects early, before bone destruction has occurred. If a lesion has developed, the prognosis is poor regardless of the material used to repair the defect. Another key is to use the matrix to prevent the extrusion of the material into the periradicular spaces.

MTA may be used to repair perforations in the furcation, coronal, mid or apical portion of the root. It must be kept moist but not wet and may be covered by amalgam or Gerestore. Another indication is to repair resorptive  perforations, if not too extensive. It will be interesting to see the research regarding the combined use of MTA and guided tissue regeneration techniques, perhaps with Atrisorb(Block Drug). Even with MTA, the surgical repair of post perforations is unpredictable unless the post is removed and the repair is made internally. Its use is contraindicated for vertical fractures. The prognosis in that situation is poor.

MTA has been approved by the FDA for many of these applications.

Coronal Leakage

The very best endodontic result is only as good as the coronal seal or the definitive restoration. This problem has often been overlooked in the presence of a well-filled root canal. What is coronal leakage? It is the intrusion of bacterial contaminants into a previously clean, well obturated endodontic filling necessitating endodontic retreatment, surgery, a combination of the two or extraction of the involved tooth.

The causes of coronal leakage include:
-Delay in getting a difinative restoration
-Recurrent decay
-Loose or missing crown
-Loose post or crown
-GP exposed to saliva for more than two weeks

Preventing Coronal Leakage

In an ideal world, every endodontic treatment should be followed by a definitive restoration at the same appointment. Unfortunately, this is not always practicle for most general dentists, nor is it possible when an endodontist refers the patient back to his or her dentist for the restorative. If the access cavity is small and the patient is compliant, Cavit is a suitable interim restoration for up to six weeks. If the defect is extensive, a seal should be placed over the gutta percha.

There is no perfect material yet as dentin bonding is not foolproof and it may be adversly affected by the sealer. ideally, the materal should be colored so as to contrast with the tooth color. It should be placed 3mm into the canals. Although such a seal may prevent coronal leakage between appointments, the material may interfere with the planned restorative treament such as post hole preparation and placement.

Awareness of this perplexing problem is the first step towards prevention. Patients must accept some of the responsibility in the following through with the recommended treatment. Practitioners must not restore a tooth exhibiting  radiographically successful endodontics where the gutta percha has been exposed to saliva directly or via recurrent decay for more than two weeks without first retreating the root canal system.

"An Endodontist's Thoughts REgarding the Referral of Endodontic Misadventures"--Reproduced with the permission from the Dentists Prefessional Liability  Trust of Colorado Newsletter.

• "I really appreciated that you could work me in the same day that Dr. Alley's office called with my need!! Also that the root canal was done the next day!! Everyone was polite and helpful. Dr. Soleimani works magic and I feel, does high quality work-painless!"
  -Renee W.
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